Amphenol Advanced Sensors
Thermometrics
Infrared Thermopile Sensors
Copyright © 2015 Amphenol. All rights reserved.
Infrared Thermopile Sensors
Non-contact Temperature Measurement
Infrared Thermopile Sensors
What is Infrared?
•
•
Form of electromagnetic wave
Extends from 0.7 m -1000 m
‒ Near infrared:
0.7 m - 2.5 m
‒ Intermediate infrared:
2.50 m - 25.0 m
‒ Far infrared:
over 25.0 m
• Most IR sensors based on two regions … 3 - 5m and 8 - 12 m
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Infrared Thermopile Sensors
Infrared Radiation
•
Electromagnetic emission and absorption
•
Occurs at the speed of light
•
Travels in a straight line
•
Takes place across a vacuum
•
Passes through many crystalline, plastic, gaseous materials
•
Does not penetrate metals
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Infrared Thermopile Sensors
Radiated Infrared Energy
The warmer the source, the more
energy it emits
W = δεT4
W = Radiant flux emitted per unit
area (W/cm2)
Infrared Sensing
 Hot objects emit infrared (IR)
and visible radiation as a
function of surface temperature
δ = Stefan-Boltzmann constant
ε = Emissivity
T = Absolute temperature of target (K)
As the temperature of the source increases,
the wavelength at which most of the energy is
radiated decreases
λmax = b/T
b = Wien’s displacement constant
 As an object gets hotter, not
only does it radiate more, but
the peak wavelengths it emits
get shorter
 Objects have different
wavelengths of radiation
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Radiation. Reflection. Transmission.
object
ε
R
ε+R+T=1
ε = emissivity
FOV
T
R = Reflectance
T = Transmittance
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Infrared Thermopile Sensors
Approximate Emissivity Figures
Material
Radiation
Material
Radiation
Paper
0.92~0.94
Aluminum (luster)
0.095
Plastic
0.95
Aluminum oxide
0.26~0.42
Ceramic
0.90
Copper (luster)
0.05
Water
0.95~0.963
Copper oxide
0.78
Human skin
0.985
Cast Iron (luster)
0.21
Paint (lusterless)
0.95
Nickel (luster)
0.045
Paint (luster)
0.9
Nickel oxide
0.37
Epoxy/Glass
0.86
Stainless steel
0.16~0.44
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Infrared Thermopile Sensors
Thermopile Construction
 Seebeck effect
A
Th
Tc=Tamb
B
+
Δ V = α ΔT = (αA- αB)(Th-Tc)
-
 To increase the sensitivity (high
Seebeck coefficient):
• Higher Th, lower T
• More thermocouples
• Heavier inert gas filling
• Thin diaphragm with lower
thermal conductance
• Highly transmitted IR filter
• High efficient IR absorber
Sensing Mechanism
Thermopile Detector Packaging
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Infrared Thermopile Sensors
What is a Thermopile?
•
Serially-interconnected array of thermocouples
•
Each thermocouple formed by the junction of two dissimilar materials
•
Thermocouple array placed across hot and cold regions of structure
•
Hot junctions thermally isolated from the cold junctions
•
Cold junctions placed on silicon substrate for effective heat sinking
•
Hot junctions formed over thin diaphragm that thermally isolates hot
and cold junctions
•
In hot regions, a black body absorbs the infrared energy, raising
temperature according to the intensity of incident energy
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Infrared Thermopile Sensors
Unique Features
Thermopile sensors have unique properties not offered by other detectors:
• Response to broad infrared spectrum
• No source of bias voltage or current needed
• Inherently stable response to DC radiation
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Infrared Thermopile Sensors
Features of Thermometrics Thermopile IR
Sensors
PRODUCT COMPARISON TABLE OF ZTP SERIES
Part Number
Package type
ZTP-101T
Thermopile Thermistor Resistance
Sensitivity(Vircal)
Filter transmittance
resistance(㏀ )
& B-Value
@Tobj=40℃
range(um)
@Tamb=25℃
@Tamb=25℃
Field of View
Lead length Window size
(mm)
(mm)
1.0mV
200
30㏀_3811
6~13
50 degree
6.7
Di a 2.5
0.6mV
50
10㏀_3970
6~13
55 degree
5
Di a 2.5
85 degree
13.5
Di a 2.4
TO-39(TO-5)
ZTP-115
ZTP-135SR
TO-46(TO-18)
1.3mV
60
100㏀_3960
6~13
Part Number
Sensor type
Main
Application
Output type
Communication
protocol
Pixel Q'ty
ZTP-115M
Si ngl e modul e
Genera l
Indus tri a l ,
Mi crowa ve Oven,
Appl i a nces , etc.
Ana l og
Vol tage
Si ngl e
Range of
Ambient
Input supply
Measuring
Temperature
voltage
Temperature(℃) Range(℃)
-40 ~ 145
-20 ~ 120
+5V
Main
Application
Mass Production
Non-contact Tempera ture
Mea s urement
Thermometry,
Medi ca l , Genera l
Indus tri a l , Occupa ncy
Detection, HVAC, etc.
Yes
Module Size
(mm)
Mass production
17 X 33
Yes
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Infrared Thermopile Sensors
Thermopile Characteristics
V = S.(TOB - TAB)
V = Output voltage from thermopile
TO = Object temperature in K
TA = Ambient temperature in K
S = Sensitivity coefficient
B = Coefficient (~4)
S and B are determined by measurement
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Infrared Thermopile Sensors
Temperature Compensation
•
Output from thermopile varies with both ambient and object temperature
•
Need to know the ambient temperature to calculate the object
temperature
•
Thermometrics standard thermopiles supplied with integrated thermistor
for compensation
•
Options include customer-specified thermistor or external
temperature compensation (no internal thermistor)
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Infrared Thermopile Sensors
Various Filter Options
Filter
Material
Transmission
Range
Application
Appliances, Microwave Oven
Standard
Silicon
6~13um
Medical, Ear Thermometer
Automotive, Tire Temperature
HVAC, Human Body Detection
F1
Silicon
8~14um
F2
Sapphire
2~5um
F3
CaF2
1~10um
NDIR
Silicon
Occupancy Detection, Intruder
alarms
Flame Detection, Analysis equipment
3.99±1%
reference
4.65±1%
CO gas detection
4.26±1%
CO2 gas detection
3.45±1%
HC gas detection
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Infrared Thermopile Sensors
Standard ZTP Series
ZTP-101T
Cap / Can
ZTP-115
ZTP-135SR
The ZTP series of IR thermopile sensors are
used for non-contact surface temperature
measurement. The product consist of thermoelements, flat IR filter, a thermistor for
temperature compensation in a hermeticallysealed TO package. There are also a variety of
filters available to help maximize performance
in specific applications.
Lead Length
Filter
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Infrared Thermopile Modules
Standard ZTP Series
Reflector
ZTP-115M
The ZTP-115M is a
single IR module. It
consists of a thermopile,
IR sensor, signal
conditioning and
voltage output.
Window
Conditioning electronics
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Infrared Thermopile Modules
ZTP-115M Signal Conditioning & Amplification
5
Output(V)
4
3
2
1
0
-20
0
20
40
60
80
100
120
140
160
o
Object Temperature( C)
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Infrared Thermopile Modules
ZTP-115M Compensated Output
Temperature Deviation ( C ).
30C
60C
90C
5
3
1
-1
-3
-5
0
10
20
30
40
50
60
70
80
90
100
Ambient Temperat ure (C)
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Infrared Thermopile Modules
ZTP-115M Field of View
1.0
Horizontal
Vertical
Normalized Output
0.8
V(-)
0.6
MODULE
H(+)
0.4
H(-)
V(+)
0.2
H(+/-) : Horizontal Direction
V(+/-) : Vertical Direction
0.0
-20
-10
0
10
20
Degree
(3) Spot Size of Normalized Output(above 10%)
Φ50
ZTP-115M
100 mm
Φ90
200 mm
Φ130
300 mm
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Infrared Thermopile Sensors
Example Interface Circuit
NTC Thermistor
used for
compensation of the
ambient factors.
Op Amp used to amplify the
output voltage signal from
the thermopile
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Infrared Thermopile Sensors
Typical Applications

Ear, Forehead Thermometry

Non-contact Temperature
Measurement Thermometry

Microwave Ovens

Induction Heater Cookers

Air Conditioners

Occupancy Detection

Lighting

Underfloor Heating Control

HVAC / Automotive
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